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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script>
        var alist01 = [];//创建一个空数组

        var alist02 = [1, 6, 3, 2, 6, 77, "haha"];

        alert(alist02.length);//7
        alert(alist02[6]);//haha
    </script>
</head>

<body>

</body>

</html>